Hot-well ejector



H. F. SCHIVI'ID T HOT WELL EJECTOR.

FILED OCT- 22,1920- Jan. 9, 1923. 1,441,301.-

INVENTOR ATTORNEY Patented Jan. 9, 1923.

\ earns *nEnaY' nsonrirn'r, or streamer/roan, PENNSYLVANIA, essrenon To wnsrlnenonsn nnne rnrc Ann nanuriio'ruarne COMPANY, A CORPORATION OF PENN- SYLVANIA.

' ""Ho'rTW'ELL nanoronfl Application filed October 22, 1920. 5 Serial Ito {118,820.

- Be-it known that I, HENRY F, SOHMIDT, a citizen of the United States, and a resident of Swarthmore, in the county of Delaware and State of Pennsylvania, have invented a new and useiul improvement in Hotell Ejectors, ofwhich thefollowing is a specification.

My i nven tionrelates to cjectors and it has particular relation-to that typeof ejector adapted to withdraw condensate from the hotwell. of a condenser andto discharge an ejectorsystein. for removing condensate from aacondenser' wherein theejector shall be POSltlVG in starting and cont1nuous.1n

"within the condenser. T

A further objectuof m'y invention is tov provide an ejectorsystem for removing con- -densate froma Condenser, wherein-the ejecting action of the condensate ejector will be automatically reestablished should the con 'densate ejector fail :to function by reason of abnormal condenser conditions.

i A further object is to-provide an overflow device for a hotwell ejector with an auxiliary ejector, whereby the condensate will be returned to the condenser. until a sufficient pressureis built up within the ejector to enable it to discharge the condensate at the required higher pressure.

I attain these objects by means of the system shown in the accompanying drawing in which the figure shown is a diagrammatic illustration of the elements of my invention- The vacuum maintained in the shell and hotwell of a surfacecondenser is generally;

phere, some means must be employed to dis-' charge the condensate agamstth1shlgher pressure. Thisis commonly accomplished by means ofa'hotwell ejector in which the steam, after expanding through the nozzle,

acquires a high velocity and imparts its velocity energy'to the-condensate, and the.

- required pressure.

operation when a normal vacuum is held the ,hotwell ejector and is preferably operlatter, passing through a velocity-pressure conversion device, has a suflicient amount of its velocity energy changed into, pressure energyso that it may discharge against the In order jto'evacuate a receptacle wherein arelatively low pressure exists it is necessary to build up a considerable pressure in theejecting device. For this reason, in the type citapparatus above mentioned, much difliculty has been experienced in starting the; ejector when a normal vacuum is held within the surface condenser. In accordance with this invention, I eliminate this .difii culty by placing an overflow in the discharge conduit of the ejector, this overflow having communication with a receiving chamber fofan auxiliary ejector. The auxiliary ejector is of the same general construction as ejectors shown in the drawing andre ferred tointhe following specification.

Referring to the drawing for amore detailed understanding of my invention, I indicate a surface condenser at lQwhich discharges condensate into a hotwellf ll. The

condensate is conducted from the hotwell 11 to a receiving chamber '12 which is associated therewith. A hotwell ejector27 is prefer ably operated on exhaust steam from noncondensing auxiliaries, or in case :of a deficiency from this source, on' lire steam, supplied by a conduit 13.

j Th' e'isteam is expanded through a nozzle 14: into amixing chamber 15 where it combines and entrains the condensate from the hotwell 11, the resultant mixture being discharged through a diffuser 16 into a discharge conduit 17 which inturn discharges-into any desired receptacle, such as a feed water heater. The discharge conduit 17 isprovidedwrth a check valve lg to prevent back flow into of an auxiliary ejector22. steamgfroman independent source is [supplied to the auxi iary ejector through a conduit 23. The

steam expands through a nozzle 24 into the mixing chamber 25 where it entrains the overflow from the hotwell ejector 27. the resultant mixture being discharged through a conduit 26 into the top portion of the surface condenser.

The operation of my device is as follows. Steam. is admitted to the supply nozzle 14, thereby entraining the condensate in the receiving chamber 12 and delivering the same through the mixing chamber 15 into the diffuser l6 and attempting to discharge it through the conduit 17 to the feed-water heater or other receptacle which is normally at atmospheric pressure. Then the ejector is started, however, there is an insufficient pressure within the diffuser 16 to discharge the condensate against. the higher atmospheric pressure and the condensate collects in the overflow chamber 19 from whence it is conducted to the receiving chamber 21 of the auxiliary ejector 22. The auxiliary ejector, operated on an independent steam supply, injects the overflow condensate directly into the upper portion of the condenser, from whence it circulates back to the hotwell. This circulation of motive fluid and condensate continues until a sufficient pressure is built up within the ejector to discharge the condensate through the diffuser 16 and check valve 18 against atmospheric pressure, when the auxiliary ejector may be shut off.

It may be preferable, however, to provide a constant supply of low-pressure steam to the auxiliaryejector since the force of the jet in the main ejector may become insufficient under abnormal conditions of operationto discharge the condensate against existing back pressure into the condensate receiving means. Such a failure of the main ejector may be due to an insufficiency of water in the hotwell to produce a solid jet,

a condition occasioned by the operation of the power plant at a light load. Another cause 'of failure of the main ejector may be the higl temperature of the condensate, ej ectors working under high vacuum condenser conditions being unable to handle water at a higher temperature than 160 F. In either case, the water or mixed water and steam, discharged by the main ejector is conveyed from the overflow chamber 19 to the receiving chamber 21 and returned by the auxiliary ejector to the condenser, fromwhence it falls again to the hotwell. This circulation through the hotwell, main and auxiliary ejectors, and condenser continues until, in one case, a sufiicient amount of water has accumulated in the hotwell the pressure built up in the main ejector and the discharge-of condensate through the conduit 17 reestablished; or in the other case, until the temperature of the water has been reduced by repeated contact with the cooling surfaces of the condenser to such a temperature as will permit the main ejector to function normally.

The advantages incident to the employment of my improved ejector system are readily apparent from the above description. The construction eliminates thedifiiculties commonly experienced in the starting of a hotavell ejector by makingprovision for auto matically starting the pumping action of the main ejector. Moreover, the automatic starting of the ejector may be accomplished under conditions of high vacuum in the condenser and of high temperature of the con densate, a condition under whichthe hotwell ejector ordinarily used in condenser installations cannot be started. It has the further advantage of being able torestart autom atically the ejection of condensate when by reason of abnormal condenser conditions, the hotwell ejector has ceased to function. This obviates the necessity of constant attention on the part of an attendant and the danger of flooding and loss of vacuum within the condenser; My improved condensate ejecting mechanism possesses the further advautage of being simple and compact in structure and efficient to a high degree in opera- -tion.

While I have shown my invention in but one form, it will be obvious to those skilled in the art that it is not so limited but is susceptible of various other changes and modifications,withontdeparting from the spirit thereof and I desire, therefore, that only such limitations shall be placed thereupon as are imposed by the prior art or as are specifically set forth in the appended claims.

lVhat I claim is:

1. In. combination with a condenser, a hotwell attachedthereto, a condensate ejector adapted to withdraw condensate from the hotwell, an overflow device at the discharge of the ejector and in'ipelling means associated with the overflow device whereby the overflow condensate may be returned to the condenser.

2. In combination with a condenser, a hotwell, a condensate ejector adapted to withdraw condensate therefrom, an overflow de vice at the discharge of the ejector and an auxiliary ejector supplying communicating means between the overflow device of the condensate ejector and the condenser.

3. In combination with a condenser, a hotwell, a condensate ejector associated therewith comprising a supply nozzle, a receiving chamber and a mixing chamber, the condensate being entrained by the supply fluid in the receiving chamber and delivered to the mixing chamber, a diffuser, an overflow device between said mixing chamber and said diffuser and impelling means associated with the overflow device to return the overflow condensate to the top portion of the ill) condenser from which it is withdrawn, and a check valve at the discharge end of said difluser.

d. In combination with a condenser having a hotwell associatd therewith, a plurality of condensate ejectors, a first ejector having an overflow device connected thereto, said ejector communicatingwith the hotwell of the condenser, and a second ejector communicating with the overflow device of the first ejector and discharging overflow condensate through a conduit to the condenser.

5. In combination with a hotwell ejector for condensers, an overflow chamber therefor, and means for evacuating said'overflow, chamber.

6. In combination with a hotweli ejector for condensers, an overflow device associated therewith, and fluid actuated means for evacuating said overflow device.

7. In combination with a hotweli ejector for condensers, an overflow device associated therewith, and impelling means for evacuating said overflow device.

8. In combination with-a hotwell ejector for condensers, an overflow device associated therewith, and fluid pressure means for exhausting said overflow device to the condenser.

In testimony whereof, I have hereunto subscribed my name this 20th day of October, 1920.v

- HENRY F. SCHMIDT. 

